Attachment for drilling machines



Dec. 23, 1958 G. R, WOLFE w 2,865,151

I ATTCHMENT FOR DRILLING MCHINES Filed Sept. 5, 1957 2 Sheets-Sheet 1 I '1 I II I a l I I .I 5 6 FI l I I l I I I I I I I I I f I 7 so 4-/ 4 3d/ I i i f 17 40 I 2 I I u 2 l I 2.9 8 I I H -15 I I I 17 I 48 ze r 49 2'0 I I II Dec. 23, 1958 G. R. woLFE ATTACHMNT FOR DRILLING MAcHINEs 2 Sheets-Sheet 2 Filed Sept. 5, 1957 niteci States Patent *i ce ,8`6,1i zwraca-Mana Fon ninmnc; Georg' R. Wo1fle, oirnbach (Main), Germany, assignor Vto M. S. 0. Maschix'lfn-nnil ASchle'ifmittelwrke lAktie'n'gesclls'chaft, Oiienbach (Main), Germany, `a German company Application :September '5, 19157, serial No. '682,232 'laim's Priority, 'application Germany September 7, 1956 '9 Clarins. (C1. '51-245) This invention relates to internal 'grinding attachments of the type adapted to be fitted to the inner spindle of a drill in order that the same may be used fo'r grinding out jbores. Since such attachments restrict the working height of thje dr-ill spindle driving them, these attachments must have las small'an overal'ljlength as Ypossible, while allowing the spindle 'bearing the vgrindin'g tool to be considerably ofiset -from the driving ldrill sp'indlc.

According vto `the 'invention there -is provided a grinding attachment adapted for connection to the "spindle of a drill, wherein a bushing ada'ptcd to car'ry an internal grinding 'spindle is mounted so as to be 'pivotable about a first pivot pin carried eccentrical'ly by ;a bearing ring. The bearing rin'g `is arranged in a housin'g of the attachment so as to be concentric with `the drill spindle, when the attachment 'is connected thereto, vand vis arranged to be driven by the drill spindle through =a countershaft and transmission means. A toothed-rim is rotatably mounted on the bearing ring and 'is :adjustable relative theret, the toothed rim being coupled to the bushing by a second pivot pin, and being arranged to be driven by the countershaft and transmission means at the same speed as the bearing ring. M w I I The bearing ring may be associatedwith a gear wheel on the countershaft through another toothed rim wh'i'ch is rigidly 'secured 'to 'the 'bearing ring, 'While the toothed rir'n which i`s rotatab'le 'on the bearing ;ring may 'en'gg'e with a 'gear wheel which ts freely 'rotatabTe 'on the countershaft. The gear wheel is drivable through the agency of planetary bevel gears mounted thereon and forming part of the transmission means. The bevel gears may be mounted on radial pins of a driving bushing secured to the countershaft and may engage with a bevel gear which can be displaced by a worm drive. Advantageously, the second pivot pin is engaged by a forked arm of the bushing, the forked arm and the first pivot pin lying opposite one another on a diameter of the bushing.

The attachment has a small overall length and permits the grinding spindle to be pivoted over a wide radius, so that the scale of adjustment can be substantially linear.

For a better understanding of the invention and to show how the same may be carried into effect, reference will now be made to the accompanying drawings, wherein:

Fig. 1 is an axial section through an attachment adapted to be fitted to the inner spindle of a drill, and

Fig. 2 is a sectional view taken along the line II-II of Fig. 1.

Referring now to the drawings, the attachment comprises a casing 2 which is releasably fianged onto the drill head 1 of a drill, and a drive shaft 3 on which is mounted a pinion 4 and which is coupled to a drill spindle, the drive shaft 3 extending into the casing 2 centrally thereof. The pinion 4 meshes with an intermediate wheel 5, which in turn, meshes with a gear wheel 6 mounted on a countershaft 7 disposed parallel to the shaft 3 in a lateral extension 8 of the casing 2.

A bushing 9 is secured to the shaft 7, the bushing 9 ra'enre Dec. 23, 1958 v2 having two diametrically opposed radially extending zpins 10 and 11, planetar'y bevel gears 12 and 13 being rotatably mounted one on each such pin. The two bevel gears 12 and 13 mesh, on opposite sides of the bushing 9, with bevel gears 14 and 15, the bevel 'gears 14 and 15 being freely rotatable on the shaft 7. The bevel gear 14 is coupled to a worm wheel 1'6 the 'position of which can be adjusted by a handle (not shown) connected to a worm 17. The setting of the worm wheel 16 can be read on a scale 30 associated in known fmanner with the handle.` The bevel gear 15 is integral with a gear wheel 18, and a gear wheel 1:9 is secured to the shaft 7.

An internal grinding spindle l20, 21 is disposed in a two-part bushing 22 which is mounted so as 'to be pivotable about a pivot pin 23 carried ecceritrically by a bearing rin'g 24. The bearing ring is rotatable in the casing 2 and carries a toothed rim 25 which meshes with the gear wheel 19. An annular toothed rim 26, concentric with the bearing ring 24 and meshing with the gear wheel 18 is rotatably secured to the bearing ring 24 between lugs 29 formed inthe bushing 22, the lugs 2:9 extendi'ng into radia'l slots formed in the bearing ring 24, and thereby serving to guide the bushing 22. The side of the bushing 22 remote from the pin 23 is provided with a forked arm 27 by means of which the bushing 22 is guided on a pivot pin 28 passing through the toothed rim 26.

The arrangernent of the gear wheels is such that, in the operation of the attachment when the worm wheel 16 is stationary, and the shaft 7 is driven by the shaft 3 through the gear train 4, 5 and 6, the gear wheel 18 rotates in the same direction as the shaft 7 and at twice the speed thereof, while the gear wheel 19 is driven at the speed of the shaft 7. Also, the Velocity ratio between the gear wheel 18 and the toothed rim 26 is twic'e a's .great as the Velocity ratio between the gear wheel 19 and the toothed lrim 25, 'and since the gear wheel 18 is driven by vthe shaft 7 at twice 'the speed of the gear wheel 19, the'two toothed r'ims 25 and 26 rotate at the same speed.

with thefive shaft '3 stationary, 'the eceenfrie setting of 'the bshing `'22 bea'rii1g`- 'the internal g'rinding spindle 20, 21 can 'be adjusted by `the wd'rin 17, since Aby 'turning the worm 17 the gear train 16, 14, 12, 13, 15 and 18 is actuated to rotate the toothed rim 26, thereby pivoting the bushing 22 about the pin 23 of the bearing ring 24. This pivoting action controls the axial relationship of shaft 3 and spindle 21. However, in the operation of the attachment With the worm wheel 16 stationary and the bushing 9 being rotated by the shaft 7, the rotation of the bushing 9 causes the two bevel gears 12 and 13 to roll on the bevel gear 14 which remains stationary and to drive the bevel gear 15 and the integral gearwheel 18. An additional advance or return motion can now be imparted to the gearwheel 18 and therefore to the toothed rim'26 by adjusting the worm 17 and therefore the bevel gear 14. Such additional motion pivots the bushing 22 around the pin 23, so that the internal grinding spindle is moved out of the position in which it is central relatively to the drill spindle. Since the pivoting radius of the bushing 22 is relatively large, the scale division on the scale 30 associated with the worm 17 can be substantially linear. The pivoting of bushing 22 causes spindle 21 to be axially offset relative to shaft 3 so that, for example, an internal bore-grinding operation can be controlled. Thus, for example, the diameter of a bore can be increased.

I claim:

1. A grinding attachment adapted for connection to the spindle of a drill, comprising a casing for connection to the drill head of a drill, a bearing ring disposed in said casing, a first pivot pin mounted eccentrically in said bearing ring, a bushing mounted in said bearing ring so as to be pivotable about said first pivot pin, and adapted to carry an internal grinding spindle, a toothed rim rotatably mounted on thebearing ring, a second pivot pin connecting said toothed rim to said bushing, a countershaft and transmission means operative on said countershaft for connecting the drill spindle to the bearing ring and the toothed rim to drive the bearing ring and the toothed rim at the same speed.

2. A grinding attachment as claimed in claim 1, comprising a gearwheel on the countershaft and a toothed rim on the bearing ring and which meshes with said gearwheel, the gearwheel being a part of said transmission means.

3. A grinding attachment as claimed in claim 1, comprising a gearwheel freely rotatable on the countershaft and planetary bevel gears on the countershaft for driving the gearwheel, the bevel gears together with said gearwheel forming a part of said transmission means, the toothed rim meshing with said gearwheel.

4. A grinding attachment adapted for connecting an internal grinding spindle to the spindle of a drill having a drill head, comprising a casing for connection to the drill head, a bearing ring disposed in said casing, a first pivot pin mounted eccentrically in said bearing ring, a bushing mounted centrally in said bearing ring and pivotable about said first pivot pin and adapted to carry the internal grinding spindle, a toothed rim rotatably mounted on the bearing ring, a second pivot pin connecting said toothed rim to said bushing, a countershaft, transmission means for connecting the drill spindle to the countershaft and connecting the countershaft to the bearing ring and the toothed rim to drive the bearing ring and the toothed rim at the same speed, and manually operable means for pivoting said bushing about said first pivot pin.

5. A grinding attachment as claimed in claim 4, wherein said manually operable means comprises a manually adjustable worm, a worm wheel operatively associated with said transmission means and meshing with the worm, the worm being operative through said worm wheel and transmission means to cause pivoting of said bushing about said first pivot pin.

6. A grinding attachment adapted for connecting an internal grinding spindle to the spindle of a drill having a drill head, comprising a casing for connection to the drill head, a bearing ring disposed in said casing, a first pivot pin mounted eccentrically in said bearing ring, a bushing mounted in said bearing ring and pivotable about said first pivot pin and adapted to carry the internal grinding spindle, a first toothed rim rotatably mounted on the bearing ring, a second pivot pin connecting said first toothed rim to said bushing, a second toothed rim fixedly attached to said bearing ring, a countershaft, a gear train for connecting the drill spindle to the countershaft, a driving bushing secured to said countershaft, diametrically opposed radial pins on said driving bushing, first and second planetary bevel gears mounted one on each of said radial pins, third and fourth bevel gears freely rotatable about said countershaft and meshing with said first and second bevel gears, a pinion integral with said fourth bevel gear and meshing with said first toothed rirn, and a gearwheel fixedly mounted on said countershaft and meshing with said second toothed rim.

7. A` grinding attachment as claimed in claim 6, wheren the first said bushing includes a forked arm which engages said second pivot pin, said first pivot pin and said forked arm lying opposite one another on a diameter of the first said bushing.

8. A grinding attachment as claimed in claim 6, wherein the first said bushing includes radially extending lugs and the bearing ring has radial slots in which the bushing is guided by said radially extending lugs, the first toothed rim being freely rotatable between said lugs.

9. A grinding attachment as claimed in claim 6, and further comprising a worm wheel fixedly mounted on said third bevel gear, and a manually adjustable worm meshing with said worm wheel, whereby adjustment of said worm is transmitted through said gears to said first toothed rim and thus, through the agency of said second pivot pin, to the first said bushing causing pivoting thereof about said first pivot pin.

References Cited in the file of this patent Nagle Aug. 13. 1957 

